import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class TcpEchoServer {
    private ServerSocket serverSocket=null;

    public TcpEchoServer(int port) throws IOException {
        serverSocket=new ServerSocket(port);
    }

    public void start() throws IOException {
        System.out.println("服务器启动");
        ExecutorService service= Executors.newCachedThreadPool();
        while(true){
            Socket clientSocket=serverSocket.accept();
            service.submit(new Runnable() {
                @Override
                public void run() {
                    processConnection(clientSocket);
                }
            });
        }
    }

    public void processConnection(Socket clientSocket){
        System.out.printf("[%s:%d]客户端上线!\n",clientSocket.getInetAddress(),clientSocket.getPort());
        try(InputStream inputStream=clientSocket.getInputStream();
            OutputStream outputStream=clientSocket.getOutputStream()){
            while(true){
                Scanner scanner=new Scanner(inputStream);
                if(!scanner.hasNext()){
                    System.out.printf("[%s:%d]客户端下线！\n",clientSocket.getInetAddress(),clientSocket.getPort());
                    break;
                }
                String request=scanner.next();
                String rseponse=process(request);
                PrintWriter printWriter=new PrintWriter(outputStream);
                printWriter.println(rseponse);
                printWriter.flush();
                System.out.printf("[%s:%d] req=%s,resp=%s\n",clientSocket.getInetAddress(),clientSocket.getPort(),request,rseponse);
            }
        } catch (IOException e) {
            throw new RuntimeException(e);
        }finally {
            try{
                clientSocket.close();
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
    }

    public String  process(String request){
        return request;
    }

    public static void main(String[] args) throws IOException {
        TcpEchoServer server=new TcpEchoServer(9090);
        server.start();
    }
}
